Merge pull request #38363 from DougGregor/racy-sleep-test-5.5

Dial back a racy race test for `Task.sleep(nanoseconds:)`.

Author: DougGregor

test/Concurrency/Runtime/async_task_sleep_cancel.swift

@@ -55,8 +55,6 @@ import Dispatch
   static func testSleepCancelledBeforeStarted() async {
     // CHECK-NEXT: Testing sleep that gets cancelled before it starts
     print("Testing sleep that gets cancelled before it starts")
-    let start = DispatchTime.now()
-
     let sleepyTask = Task {
       try await Task.sleep(nanoseconds: UInt64(pause))
     }
@@ -65,20 +63,14 @@ import Dispatch
       sleepyTask.cancel()
       try await sleepyTask.value
 
-      fatalError("sleep(nanoseconds:) should have thrown CancellationError")
+      print("Bah, weird scheduling")
     } catch is CancellationError {
-      // CHECK-NEXT: Caught the cancellation error
       print("Caught the cancellation error")
-
-      let stop = DispatchTime.now()
-
-      // assert that we stopped early.
-      assert(stop < (start + .nanoseconds(pause)))
     } catch {
       fatalError("sleep(nanoseconds:) threw some other error: \(error)")
     }
 
-    // CHECK-NEXT: Cancelled!
+    // CHECK: Cancelled!
     print("Cancelled!")
   }